06. İYTE Araştırma Merkezleri / IZTECH Research Centers

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Citation - WoS: 50
Citation - Scopus: 54
Assessment of Different Nanofiltration and Reverse Osmosis Membranes for Simultaneous Removal of Arsenic and Boron From Spent Geothermal Water
(Elsevier, 2021) Jarma, Yakubu A.; Baba, Alper; Karaoğlu, Aslı; Tekin, Özge; Baba, Alper; Ökten, H.Eser; Tomaszewska, Barbara; Kabay, Nalan; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
One of the factors that determine agricultural crops’ yield is the quality of water used during irrigation. In this study, we assessed the usability of spent geothermal water for agricultural irrigation after membrane treatment. Preliminary membrane tests were conducted on a laboratory-scale set up followed by mini-pilot scale tests in a geothermal heating center. In part I, three commercially available membranes (XLE BWRO, NF90, and Osmonics CK- NF) were tested using a cross-flow flat-sheet membrane testing unit (Sepa CF II, GE-Osmonics) under constant applied pressure of 20 bar. In part II, different spiral wound membranes (TR-NE90-NF, TR-BE-BW, and BW30) other than the ones used in laboratory tests were employed for the mini-pilot scale studies in a continuous mode. Water recovery and applied pressure were maintained constant at 60% and 12 bar, respectively. Performances of the membranes were assessed in terms of the permeate flux, boron and arsenic removals. In laboratory tests, the permeate fluxes were measured as 94.3, 87.9, and 64.3 L m?2 h?1 for XLE BWRO, CK-NF and NF90 membranes, respectively. The arsenic removals were found as 99.0%, 87.5% and 83.6% while the boron removals were 56.8%, 54.2%, and 26.1% for XLE BWRO, NF90 and CK-NF membranes, respectively. In field tests, permeate fluxes were 49.9, 26.8 and 24.0 L m?2 h?1 for TR-NE90-NF, BW30-RO and TR-BE-BW membranes, respectively. Boron removals were calculated as 49.9%, 44.1% and 40.7% for TR-BE-BW, TR-NE90-NF and BW30-RO membranes, respectively. Removal efficiencies of arsenic in mini-pilot scale membrane tests were all over 90%. Quality of the permeate water produced was suitable for irrigation in terms of the electrical conductivity (EC) and the total dissolved solids (TDS) for all tested membranes with respect to guidelines set by the Turkish Ministry of Environment and Urbanisation (TMEU). However, XLE BWRO, CK-NF and NF90 membranes failed to meet the required limits for irrigation in terms of boron and arsenic concentrations in the product water. The permeate streams of TR-BE-BW, TR-NE90-NF and BW30-RO membranes complied with the irrigation water standards in terms of EC, TDS and arsenic concentration while boron concentration remained above the allowable limit. © 2020 Elsevier B.V.
Citation - WoS: 30
Citation - Scopus: 35
Assessment of Geothermal Energy Use With Thermoelectric Generator for Hydrogen Production
(Pergamon-Elsevier Science LTD, 2021) Hadjiat, M. M.; Hancıoğlu, Ebru; Mraoui, A.; Ouali, S.; Hancıoğlu Kuzgunkaya, Ebru; Salhi, K.; Ouali, A. Ait; Benaouda, N.; 01. Izmir Institute of Technology
In this work, a new model for producing hydrogen from a low enthalpy geothermal source was presented. Thermal energy from geothermal sources can be converted into electric power by using thermoelectric modules instead of Organic Rankine Cycle (ORC) machines, especially for low geothermal temperatures. This electrical energy uses the water electrolysis process to produce hydrogen. Simulation and experiments for the thermoelectric module in this system were undertaken to assess the efficiency of these models. TRNSYS software is used to simulate the system in Hammam Righa spa, the temperature of this spring is 70 degrees C. Obtained results reveal that in hammam righa spa in Algeria, 0.5652 Kg hydrogen per square meter of thermoelectric generator (TEG) can be produced in one year. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Citation - WoS: 41
Citation - Scopus: 58
Current Status and Perspectives of Protease Inhibitors and Their Combination With Nanosized Drug Delivery Systems for Targeted Cancer Therapy
(Dove Medical Press Ltd, 2021) Rudzinska, Magdalena; Dağlıoğlu, Cenk; Dağlıoğlu, Cenk; Savvateeva, Lyudmila, V; Kaci, Fatma Necmiye; Antoine, Rodolphe; Zamyatnin, Andrey A., Jr.; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of Technology
In cancer treatments, many natural and synthetic products have been examined; among them, protease inhibitors are promising candidates for anti-cancer agents. Since dysregulated proteolytic activities can contribute to tumor development and metastasis, antagonization of proteases with tailored inhibitors is an encouraging approach. Although adverse effects of early designs of these inhibitors disappeared after the introduction of next-generation agents, most of the proposed inhibitors did not pass the early stages of clinical trials due to their nonspecific toxicity and lack of pharmacological effects. Therefore, new applications that modulate proteases more specifically and serve their programmed way of administration are highly appreciated. In this context, nanosized drug delivery systems have attracted much attention because preliminary studies have demonstrated that the therapeutic capacity of inhibitors has been improved significantly with encapsulated formulation as compared to their free forms. Here, we address this issue and discuss the current application and future clinical prospects of this potential combination towards targeted protease-based cancer therapy.
Citation - WoS: 31
Citation - Scopus: 35
Distribution of Geothermal Arsenic in Relation To Geothermal Play Types: a Global Review and Case Study From the Anatolian Plate (turkey)
(Elsevier, 2021) Baba, Alper; Uzelli, Taygun; Uzelli, Taygun; Baba, Alper; Sözbilir, Hasan; 03.03. Department of Civil Engineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of Engineering
Arsenic has a natural cycle as it travels underground. It can mix with geothermal fluid in different ways under the control of magmatic and tectonic processes. Geogenic arsenic is present in many geothermal fields in the world at concentrations above the limits set for human health. The arsenic content of geothermal fluids is also related to the concept of geothermal play type, which forms geothermal systems, because the natural processes that form the geothermal system also control the arsenic cycle. In this study, an attempt is made to explain the relationship between the geothermal play type concept and geothermal arsenic circulation. For this purpose, geothermal field examples are given from around the world and Turkey. The result shows that arsenic concentrations can reach significant levels along with plate tectonic boundaries in the world. When arsenic concentrations were evaluated, the effect of major faults on the Anatolian Plate was clearly seen. Also, in the Anatolian plate where volcanosedimentary units are common, geothermal fluids caused more effective alteration along with structural control and increased arsenic concentrations in geothermal systems. This interaction between structural elements, geothermal fluid, and the arsenic cycle shows that the concept of play type in geothermal systems should also be taken into consideration. It was determined that the places with high arsenic values are located within the convective-non-magmatic extensional geothermal play types such as Western Anatolian Extensional System and the North Anatolian Fault. The concept of play type in geothermal systems includes all systematic and external factors that make up these processes. For this reason, it is very important to evaluate the play type classification together with the arsenic cycle.
Citation - WoS: 3
Citation - Scopus: 3
Effects of Different Lipopolysaccharide Preparations on Neutrophil Function in the Fathead Minnow, Pimephales Promelas Rafinesque
(John Wiley and Sons Inc., 2011-11) Jovanovic, B.; Baran, Ezgi; Goetz, F. W.; Palic, D.
The fish innate immune response to pathogensrelies on the adequate function of neu trophilicgranulocytes (Palic´, Andreasen, Herolt, Menzel &Roth 2006). The ability of neutrophils to phago-cytose microor ganisms and cellular debris is essen-tial for normal development an d survival of animalpopulations (Segal 2005). The evaluation of neu-trophil function is valuable for assessing the healthstatus of individuals and fish populations (Smith &Lumsden 1983). Resistance of fishes to septic shockand tolerance to high concentrations of lipopoly-saccharide (LPS) was observed as a major differencebetween mammalian and fish innate immuneresponses (Berczi, Bertok & Bereznai 1966). Thisfunctional difference could be attri buted to severalcostimulatory molecules and intracellular mediatorsbeing absent in fish, but active in mammals duringresponse to LPS stimulation (Iliev, Roach, Mac-kenzie, Planas & Goetz 2005). Most fish do notpossess a Toll-like receptor (TLR) with sequencesimilarity to mammalian TLR4 (Leulier & Lemai-tre 2008) and the ones that do have no ability forTLR4 downstream signalling (Sepulcre, Alcaraz-Perez, Lopez-Munoz, Roca, Meseguer, Cayuela &Mulero 2009). Regardless of the absence andfunctionality of TLR4 and costimulatory molecules,bacterial LPS can induce a robus t inflammatorygene response in innate immune fish cells, but atconcentrations 1000-fold higher than is commonlyobserved in mammalian species ( lgmL)1vs.ng mL)1) (Palic´, Ostojic, Andreasen & Roth2007; Mackenzie, Roher, Boltan˜a & Goetz 2010).In contrast, ultrapure LPS preparations are rela-tively inactive in fish (Iliev et al. 2005).
Citation - WoS: 46
Citation - Scopus: 52
Extracellular Enzyme Production and Enterotoxigenic Gene Profiles of Bacillus Cereus and Bacillus Thuringiensis Strains Isolated From Cheese in Turkey
(Elsevier Ltd., 2009-09) Molva, Çelenk; Molva, Çelenk; Sudağıdan, Mert; Okuklu, Burcu; Okuklu, Burcu; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
The aim of the present study was to investigate the biochemical characteristics, extracellular enzyme production and enterotoxigenic genes contents of 6 Bacillus cereus and 22 Bacillus thuringiensis strains, isolated from 100 cheese samples in Turkey. Crystal morphologies of B. thuringiensis strains were found either spherical (n = 12) or spherical and irregular-shaped (n = 10) by phase contrast microscopy. B. cereus and B. thuringiensis strains were found to produce extracellular enzymes, respectively: gelatinase (83% and 91%), DNase (83% and 77%), lecithinase (83% and 95%), protease on skim milk agar (100% and 100%), protease on milk agar (100% and 91%), protease on casein agar (83% and 77%), xylanase (100% and 45%), and cellulase (0% and 41%), and amylase (83% and 27%). All of the strains, except for Bt-D1, hydrolyzed Tween 20 (96%), but not Tween 80 or tributyrin. Pectinolytic activity was obtained to be the least frequent (4%). PCR analysis showed that all strains contained nheA, nheB, nheC and hblD genes. The hblA and hblC genes were present in 2 and 4 of B. thuringiensis strains, respectively. The bceT gene was detected in 1 B. cereus and 9 B. thuringiensis strains. The entFM gene was detected more frequently in B. thuringiensis (82%) than in B. cereus strains (50%). To our knowledge, this is the first report about the isolation and identification of enterotoxigenic B. cereus and B. thuringiensis strains from cheese samples in Turkey.
Citation - WoS: 5
Citation - Scopus: 6
A Novel Land Surface Temperature Reconstruction Method and Its Application for Downscaling Surface Soil Moisture With Machine Learning
(Elsevier, 2024) Güngör, Şahin; Güngör, Şahin; Gündüz, Orhan; Gündüz, Orhan; 03.10. Department of Mechanical Engineering; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Downscaling of soil moisture data is important for high resolution hydrological modeling. Most downscaling studies in the literature have used spatially discontinuous land surface temperature (LST) maps as the main auxiliary parameter, which limits the creation of continuous soil moisture maps. The number of studies on soil moisture downscaling with machine learning that use gapless LST maps is limited. With this motivation, a hybrid reconstruction method has been proposed in this study to practically obtain continuous LST maps, which are then used to produce high resolution surface soil moisture (SSM) datasets. The proposed method is shown to have high mean performance with R2 and RMSE values of 0.94 and 1.84°K, respectively, for the period between 2019 and 2022. The developed reconstructed LST maps were then used to downscale original 9 km spatial resolution soil moisture datasets of SMAP L3 and SMAP L4 with Random Forest (RF) machine learning algorithm. The RF model were run with four different rainfall datasets, and the MSWEP rainfall dataset was found to produce the best results. The use of antecedent rainfall values as input variables in machine learning models has been shown to improve the performance of the models R2 0.76 to 0.93. The accuracy of the downscaled data was later evaluated for Western Anatolia Basins (WAB) in Türkiye with 31 in-situ stations. The downscaled SMAP L4 had good average statistical indicators R (0.815 ± 0.1), RMSE (0.09 ± 0.047 cm3/cm3), and ubRMSE (0.058 ± 0.025 cm3/cm3). Downscaled SMAP L3 was also validated with in-situ observations with satisfactory R (0.79 ± 0.074), RMSE (0.09 ± 0.043 cm3/cm3), and ubRMSE (0.06 ± 0.026 cm3/cm3) statistics. Furthermore, the performance of the downscaled SMAP L3 was also cross validated with SMAP + Sentinel 1 (L2) dataset between 2019 and 2022. The mean statistics of R (0.761 ± 0.11) and Root Mean Squared Difference (RMSD) (0.05 ± 0.014 cm3/cm3) between downscaled SMAP L3 and L2 data revealed that the new reconstruction method of LST used in the RF model for downscaling of soil moisture performed well to obtain high resolution soil moisture datasets. The proposed technique also overcame the difficulties associated with coastal regions where data was masked for quality considerations, by not only enhancing overall spatial resolution but also filling these data gaps and giving a complete SSM coverage. © 2024 Elsevier B.V.
Citation - WoS: 102
Citation - Scopus: 122
Prevalence of Staphylococcal Enterotoxins, Toxin Genes and Genetic-Relatedness of Foodborne Staphylococcus Aureus Strains Isolated in the Marmara Region of Turkey
(Elsevier Ltd., 2011-08) Aydın, Ali; Sudağıdan, Mert; Muratoğlu, Karlo
Staphylococcus aureus is a major foodborne pathogen and it has the ability to produce a number of extracellular toxins. We analyzed 1070 food samples obtained from retail markets and dairy farms in the Marmara Region of Turkey for the presence of S. aureus. Out of 147 isolates, 92 (62.6%) were enterotoxigenic. PCR was used to investigate the presence of staphylococcal enterotoxin genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq and seu), exfoliative toxin genes (eta and etb) and the toxic - shock syndrome toxin gene (tst). The PCR results showed that 53.3% of the isolates contained staphylococcal enterotoxin-like (SEl) toxin genes (seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq and seu) which were more frequent than classical enterotoxin genes (sea to see). Furthermore, seo, sei, sem, seg, seu and sec were found in 37.0, 32.7, 30.4, 29.3, 29.3 and 27.2% of the isolates, respectively. The tst gene was detected and confirmed by DNA sequencing in 9 isolates. The presence of eta and etb were not found in the isolates. Enterotoxigenic capabilities of isolates with SEA-SEE were investigated by ELISA. Enterotoxigenic S. aureus isolates produced one to three enterotoxins, with the most frequently produced types being enterotoxin A and C. There was a correlation of 72.1% between production of a specific toxin and the presence of the respective genes. PFGE analysis was used to identify genetic-relatedness of enterotoxigenic S. aureus isolates and the results revealed that 13 groups of isolates from different or the same origin that contained the same genes showed 100% homology with indistinguishable band patterns. The other enterotoxigenic isolates showed related band patterns with 72-86% homology in sea-, 61-90% homology in sec-, 80-96% homology in seh-, and 69-96% homology in sep-positive isolates. To our knowledge, this is the first study to examine enterotoxins and related gene contents of S. aureus food isolates in the Marmara Region of Turkey.
Citation - WoS: 83
Citation - Scopus: 91
Source of Arsenic Based on Geological and Hydrogeochemical Properties of Geothermal Systems in Western Turkey
(Elsevier Ltd., 2012-12) Baba, Alper; Baba, Alper; Sözbilir, Hasan; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Turkey is an area of complex geology with active tectonics and high geothermal potential. Especially, the western part of Turkey is a region of abundant geothermal activity. Faults accommodating the deep circulation of hydrothermal fluids of meteoric origin are the primary means by which of geothermal systems are controlled in this region. Many of the thermal activities are related to the improved dilation on the ~E-W-strikes of the graben faults. This situation serves as a suitable environment for the presence of high levels of arsenic in geothermal water resources. The highest concentrations of naturally occurring aqueous arsenic (As) are found in certain types of geothermal waters, generally those related to major graben faults. In this regard, high arsenic concentrations in geothermal resources have been detected in Western Turkey, including but not limited to Biga Peninsulla, Gediz Graben, Kucuk, and Buyuk Menderes Graben with values ranging from 1 to 1419ppb in geothermal fluids. The thermal waters have surface temperatures of up to 100°C and reservoir temperatures range from 150 to 248°C in the Menderes Graben, from 120 to 287°C in the Gediz Graben, and from 153 to 174°C in Biga Peninsula. Hydrogeochemically, the Menderes graben and Gediz Graben thermal waters are of the Na-HCO3, Ca-HCO3, and Na-SO4 types, whereas some geothermal fluids such as those of Tuzla and Kestanbol in the Biga Peninsula, Çeşme, and Urla are of the Na-Cl type.
Citation - WoS: 28
Citation - Scopus: 34
Statistical Downscaling of Grace Twsa Estimates To a 1-Km Spatial Resolution for a Local-Scale Surveillance of Flooding Potential
(Elsevier, 2023) Khorrami, Behnam; Pirasteh, Saied; Ali, Shoaib; Şahin, Onur Güngör; Vaheddoost, Babak
The Gravity Recovery and Climate Experiment (GRACE) paved the way for large-scale monitoring of the hydrological extremes. However, local scale analysis is aslo challenging due to the coarse resolution of the GRACE estimates. The feasibility of the downscaled GRACE data for the flood monitoring in the Kizilirmak Basin (KB) in Turkiye is investigated in this study by integrating the GRACE and hydrological model outputs of a random forest approach. Results suggest that the TWSA, over the Asagi Kizilirmak Basin (AKB), is ascending with an annual rate of + 3.51mm/yr; while the Orta Kizilirmak Basin (OKB), Yukari Kizilirmak Basin (YKB), Delice Basin (DB), Develi Kapali Basin (DKB), and Seyfe Kapali Basin (SKB) showed descending trend respectively as -1.15mm/yr, -1.58mm/yr, -1.14mm/yr, -2.34mm/yr, and -1.31mm/yr. The hydrological status of the basin showed that in 2003, 2005, 2010-2013, and 2015-2016 periods the study area was prone to the inundation. Hence, by validating the Flood Potential Index (FPI) rates acquired from the downscaled GRACE data, it was shown that the best correlation coefficient (0.73) between FPI and streamflow (Q) is associated with the SKB. It is also concluded that the downscaled TWSA associated with the fine-resolution models depicts acceptable accuracy in determination of the flood potential at local scales.
Citation - WoS: 51
Citation - Scopus: 66
Utilization of Renewable Energy Sources in Desalination of Geothermal Water for Agriculture
(Elsevier, 2021) Tomaszewska, Barbara; Gökçen Akkurt, Gülden; Gökçen Akkurt, Gülden; Baba, Alper; Kaczmarczyk, Michal; Bujakowski, Wieslaw; Keleş, Nazlı; Jarma, Yakubu A.; Baba, Alper; Bryjak, Marek; Kabay, Nalan; 03.03. Department of Civil Engineering; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
The agricultural sector, which is highly dependent on water, is urged to build on improved water management practices and explore available options to match supply and demand because of the water scarcity risks and a sustainable and productive agri-food chain. Geothermal water is an energy source used to generate electricity and/or heat. After harnessing its energy, the remaining water can be used as a water source for irrigation following treatment because of its high ionic content. Geothermal fields are mostly located in rural areas where agricultural activities exist. This would be a good match to decrease the transportation cost of irrigation water. The energy demand of the desalination process for agriculture is higher, requiring additional post-treatment processes. Fossil fuels to fulfill the energy requirements are becoming expensive, and greenhouse gas emissions are harmful to the environment. Thus, efforts should be directed towards integrating renewable energy resources into desalination process. This work focuses on presenting a comprehensive review of geothermal water desalination which is powered by renewable energy and provides specific cases from Turkey and Poland. Furthermore, possible new generation renewable energy systems in desalination are introduced, considering their potential application in the desalination of geothermal water for agricultural irrigation.
Citation - WoS: 20
Citation - Scopus: 19
Virulence Properties of Methicillin-Susceptible Staphylococcus Aureus Food Isolates Encoding Panton-Valentine Leukocidin Gene
(Elsevier Ltd., 2010-04) Sudağıdan, Mert; Aydın, Ali
In this study, three Panton-Valentine Leukocidin gene carrying methicillin-susceptible Staphylococcus aureus (MSSA) strains (M1-AAG42B, PY30C-b and YF1B-b) were isolated from different food samples in Kesan-Edirne, Turkey. These strains were characterized on the basis of MLST type, spa type, virulence factor gene contents, antibiotic susceptibilities against 21 antibiotics and biofilm formation. The genetic relatedness of the strains was determined by PFGE. In addition, the complete gene sequences of lukS-PV and lukF-PV were also investigated. All strains were found to be susceptible to tested antibiotics and they were mecA negative. Three strains showed the same PFGE band pattern, ST152 clonal type and t355 spa type. In the detection of virulence factor genes, sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq, seu, eta, etb, set1, geh and tst genes were not detected. All strains showed the positive results for α- and β-haemolysin genes (hla and hlb), protease encoding genes (sspA, sspB and aur), lukE and lukD leukocidin genes (lukED). The strains were found to be non-biofilm formers. By this study, the virulence properties of the strains were described and this is one of the first reports regarding PVL-positive MSSA strains from food. © 2010 Elsevier B.V.

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